This invention relates generally to computer printers and in particular to a method for visually indicating the printer status.
Printers for personal computers such as the Hewlett-Packard DeskJet.RTM. family of printers typically contain a carriage that moves back and forth across a sheet of paper ("media") during the printing operation. The carriage contains one or more printer cartridges ("pens") that apply ink to the media to form the printed image. The carriage side to side positioning is along a set of coordinates arbitrarily defined as the x axis while the media direction through the printer is considered the y axis.
Following the introduction of color printing, it is now common to find two or more pens on the carriage. In most cases, a black pen, containing a black pigment based ink, and a three color pen, containing the complementary colors of cyan, magenta, and yellow, are used. Separate color pens for the cyan, magenta, and yellow colors may also be used. The black pen is optimized for high contrast monochrome printing such as the printing of text while the color pen is used to print color images. In most cases, the color pen and the black pen have their own ink supply. Alternatively, the ink supply may be located in a separate ink reservoir and supplied to the pens via flexible tubing in a technology referred to as "off axis printing".
The black pen and the color pen each contain complex circuitry typically in the form of an integrated circuit which operates to receive image data from the printer as the carriage travels along the x axis and apply ink to the media from a set of nozzles responsive to the image data. Each of the pens in turn communicates back to the controller in the printer with status information such as ink supply and pen functionality. The controller also verifies that the type of pen is properly matched to the particular model of printer. The pens are therefore a major component of the printer which direct affect print quality and require user attention for maintenance or replacement. Printer status is a collection of information about the present state of the printer and typically includes ink supply and pen functionality. It would be desirable to provide a user friendly method for indicating printer status which does not add substantial manufacturing cost to the printer.
In order for the printer to function properly, all of the pens must have an adequate supply of ink, must be properly matched to the printer type, and must otherwise be functional. If any of these conditions are not met, the user is left to troubleshoot the printer and determine what the problem is. Prior art inkjet printers such as the HP Deskjet.RTM. 895 printer have a single LED (light emitting diode) indicator on the printer control panel that lights to indicate that there is an inadequate supply of ink in one of the pens but does not indicate which pen is affected. It would be desirable to provide a method for indicating printer status in greater detail that is visual and intuitive.
It was discovered that the carriage of an inkjet printer could be used to indicate the printer settings. In the HP Deskjet.RTM. 310 printer, a printer settings menu having selections for the character set, text scaling, perforation skip, media source, and so on is located adjacent to the carriage. A pointer on the carriage is used to point to a particular setting by moving the carriage to a selected position along the x axis. However, this method addresses only a setup mode for static printer setup parameters and does not provide for the indication of current printer status. However, merely indicating printer settings which were originally set by the user is not by itself useful for communicating the printer status in order to facilitate troubleshooting and correcting problems.
Therefore, it would be desirable to provide a method for indicating the condition of the pens using the carriage to visually point to a set of condition indicators.